1. Field of Invention
The present invention relates to a projection display device which separates light beams from a light source into red, blue and green light beams, modulates these light beams through modulation elements such as liquid crystal panels in response to image information, synthesizes the modulated light beams by a light synthesizing element, and enlarges and projects the light beams on a projection screen by a projection system.
In particular, the present invention relates to a mounting mechanism of a liquid crystal panel to a prism composite constituting a light synthesizing element in this type of projection display device.
2. Description of Related Art
Japanese Patent Application Laid-Open No. 10-10994 discloses a projection display device in which a fixed frame is fixed to the light incident face of a light synthesizing element (a prism composite), and a modulation element frame is detachably mounted to the fixed frame, positioned by a position adjusting member, and then fixed by a fixing member.
In this projection display device, a modulation element is securely positioned and fixed to the light synthesizing element. Hence, displacement in pixel combination can be reduced and the focus can be exactly adjusted. As a result, higher definition can be readily achieved. In addition, the projection display device has a configuration capable of exchanging the modulation element and a miniaturized light synthesizing element, so that the resulting commercial product is compact, lightweight, and highly reliable in spite of external disturbances.
More compact and lightweight projection display devices having higher definition have been required, and thus modulation elements having a pitch which is two-third of the current pixel pitch are being developed.
In a conventional projection display device, however, if the pixel pitch is further decreased, pixel displacement may occur when being allowed to stand at a high or low temperature for a long time after being used at high temperature.